As the population ages, it is becoming a very important task for the society to address lifestyle-related diseases of adults. In particular, in the case of a disease related to high blood pressure, it is recognized that collection of blood pressure data for a long term is very important. From such a viewpoint, various biologic information detecting apparatuses for detecting blood pressure or the like have been developed.
One of conventional apparatuses for detecting biologic information by using an external ear is a patient monitoring apparatus which is inserted in an ear canal or another region in an external ear and is always attached (refer to, for example, Patent Document 1). Patent Document 1 discloses, as a method of detecting a pulse wave of an artery or a blood flow, a method of emitting light from a light emitting element to a living body, receiving the light scattered by an artery in the living body or a blood cell in an artery by a light receiving element, and detecting a pulse wave or a blood flow from the scattered light. According to the method, pulsation, pulse wave, heart beat, body temperature, arterial oxygen saturation, blood pressure, and the like can be calculated from a light reception amount of scattered light of infrared light or visible light emitted into a living body.
As a device attached to an ear canal or earlobe, there is an emergency information device having radio communication means and including arterial oxygen saturation sensor, a body temperature sensor, a heart beat sensor, and a pulse wave sensor (refer to, for example, Patent Document 2).
On the other hand, with respect to measurement of blood pressure, a blood pressure measuring apparatus using a pulsation waveform of a blood vessel is accepted as one of dominant blood pressure measuring methods besides a blood pressure measuring apparatus (refer to, for example, Non-Patent Document 1) according to a cuff oscillometric method, a volume compensating method, or the like as another method.
In the application, the name of “auricle” is according to Non-Patent Document 2, and the names of auricular cartilages are according to Non-Patent Document 3.    [Patent Document 1] Japanese Patent Application Laid-open No. 9-122083    [Patent Document 2] Japanese Patent Application Laid-open No. 11-128174    [Non-Patent Document 1] Kenichi Yamakoshi and Tatsuo Togawa, “Biologic sensors and measuring apparatuses”, edited by Japanese Society for Medical and Biological Engineering (JSMBE), ME textbook series A-1, pp 39 to 52    [Non-Patent Document 2] “Illustrated Human Anatomy Vol. 1 (translation supervisor: Michio Okamoto), Sobotta, p. 126, Igaku-shoin Limited, issued on Oct. 1, 1996    [Non-Patent Document 3] “Illustrated Human Anatomy Vol. 1 (translation supervisor: Michio Okamoto), Sobotta, p. 127, Igaku-shoin Limited, issued on Oct. 1, 1996